Auxiliary stack holder



Nov. 29, 1966 R. STUART AUXILIARY STACK HOLDER 5 Sheets-Sheet 1.

Filed Jan. 29, 1964 W I INVENTOR RosER T STU/1R7- Nova 29, 1966 R. STUART AUXILIARY STACK HOLDER Filed Jan. '29, 1964 5 Sheets'Sheet 2 Q. a. \m W HI! I; 1] I m INVENTOR.

ROBERT STUART 8W ATW av. 29, 1966 R. STUART 3,288,463

AUXILIARY STACK HOLDER Filed Jan. 29, 1964 5 Sheets-Sheet 5 m INVENTOR. m ROBERT 5711A 0m Z9, 16 R. s'ruART AUXILIARY STACK HOLDER 5 Sheets-Sheet 4 Filed Jan. 29, 1964 g m mg INVENTOR.

i? R. STUART 3,288,463

AUXILIARY STACK HOLDER Filed Jan. 29, 1964 5 Sheets-Sheet a INVENTOR. RoBER T STU/4R7 United States Patent 3,288,463 AUXILIARY STACK HOLDER Robert Stuart, Chicago, IlL, assignor to National Can Corporation, Chicago, Ill., a corporation of Delaware Filed Jan. 29, 1964, Ser. No. 340,935 6 Claims. (Cl. 271-62) This invention relates to improvements in sheet handling apparatus, and more particularly to apparatus employed to support a pile of sheets for feeding one after another from the top of the pile.

In the handling of heavy sheets, such as tinplate, preparatory to feeding them into a decorating press, the sheets are customarily fed one at a time into the press from a stack of the sheets on a skid that is, in turn, supported by a pile elevator. As the sheets are fed from the top of the pile, the elevator is progressively raised so that the top of the stack is maintained at the proper feeding level. When the supply of sheets on the skid becomes depleted the elevator must be lowered, the empty skid removed, and a loaded skid placed on the elevator which is then raised to the proper feeding level. During the time required to unload from the elevator the empty skid and reload thereon the new skid, the feeding of the sheets must be discontinued, resulting in loss of production, unless provision is made for temporarily supporting, in proper feeding position during the skid changeover interval, a few remaining sheets on the skid that is to be on loaded.

It is an object of the present invention to provide an improved sheet handling apparatus that temporarily supports, in feeding position, the last few sheets on a skid during the time required to lower the pile elevator and unload therefrom that skid, reload the elevator with another skid having a fresh supply of sheets, then raise the loaded skid to proper position, and then withdraw the support from said last few sheets so that they become the top group of sheets of the loaded skid, all of which permits continuous feed of the sheets into the press dur ing the skid changeover period.

It is a further object of the present invention to provide apparatus of the type stated which can be used in conjunction with various sizes of existing sheet feeders and with existing skids.

It is another object of the present invention to provide apparatus of the type stated which is relatively inexpen' sive, is easily installed, and is readily operated by relatively unskilled persons.

It is an additional object of the present invention to provide apparatus of the type stated which includes a plurality of forks that may be readily shifted together for insertion between the sheets and the skid supporting same and then readily retracted from sheet-supporting position when the skid with the fresh supply of sheets is raised to proper position.

The attainment of the above and further objects of the present invention will be apparent from the following specification taken in conjunction with the accompanying drawing forming a part thereof.

In the drawing:

FIG. 1 is a fragmentary side elevational view of sheet handling apparatus constructed in accordance with and embodying the present invention, and showing the forked inserter in the retracted position;

FIGS. 2 and 3 are fragmentary sectional views taken along lines 22 and 3-3 respectively, of FIG. 1;

FIG. 4 is a fragmentary sectional view, on an enlarged scale, taken along line 44 of FIG. 1;

FIG. 5 is a fragmentary sectional view, on an en larged scale, taken along line 5-5 of FIG. 2;

FIG. 6 is a side elevation-a1 view similar to FIG. 1 and showing the forked inserter in sheet-supporting position;

3,288,463 Patented Nov. 29, 1966 FIG. 7 is a fragmentary top plan view of a fork-lock ing mechanism that forms part of the present invention; and

FIG. 8 is a fragmentary sectional view taken along line 8-8 of FIG. 7.

Referring now in more detail and by reference characters to the drawing, which illustrates a preferred embodiment of the present invention, 1 designates a sheet handling and feeding apparatus having a base frame 3 that includes front and rear uprights 5, 5, 7, 7, and upper cross members 8, 8 joined to the uprights. Within the uprights 5, 5, 7, 7, is a pile elevator 9 which may be of a known type as, for instance, that shown in Martin Patents 2,218,401 and 2,626,800, and Schneider Patent 2,437,792. Sufiice it to say that the pile elevator 9 includes a platform 11 to which a pair of sash chains 13, 13 are attached at each side. The sash chains 13, 13 are trained around sprockets 1.5, 15 which are mounted upon parallel shafts 17 (one being shown) which are at opposite sides of the frame 3, the shafts being suitably journaled and driven in a conventional manner shown in the aforesaid Martin and Schneider patents.

The elevator platform 11 is adapted to support a skid 19 upon which there is loaded a stack of sheets 21 of -tin plate or the like, and the sheets of the stack 21 are separated and forwarded for delivery to a metal decorating press by a suitable sheet feeding mechanism 23 which may be of a known type, for example that shown in Baker et al. Patent 2,247,466 or Williams Patent 2,230,633. Such mechanism includes suction sheet separators 25, 25

and suction sheet forwarders 27, 27. Since the mounting, construction and operation of the sheet forwarders and separators is known in the art and is shown in the aforesaid Baker et al. and Williams patents, these details are not shown or described herein. Furthermore, the fragmentary portion of the mechanism 23 that is shown in FIGS. 3 and 4 is omitted from the remaining figures.

The elevator platform 11 may be rapidly lowered to a suitable level to load a skid with a pile of sheets thereon, and thereafter the elevator platform may be rapidly raised to bring the top edge of the stack 21 to the proper position for separation and feeding by the mechanism 23, all in a manner known in the art. Furthermore, the shafts 17 may thereafter be intermittently rotated to raise the elevator platform 11 progressively as the sheets are removed from the top of the stack, thereby to maintain the top of the stack at the proper feeding level. Any suitable mechanism for imparting progressive movement to the shafts 17 may be used, for example those shown in Williams Patent 2,230,633 or Baker Patent 2,149,130.

The apparatus 1 also comprises a generally horizontal U-shap'ed frame 29 that includes a pair of channel-shaped side members 31, 33 and a fork-supporting bar 35 that constitutes the bight of the frame and which extends at right angles to the side members 31, 33 near corresponding ends thereof. Rigidly mounted on the side members 31, 33 adjacent to the ends of the fork-supporting bar 35 are pivot bars 37, 39 for journalling axially aligned pivot pins 40, 41. The ends of the bar 35 have brackets 43, 45 bolted or otherwise rigidly secured thereto, and the pins 40, 41 are secured to the brackets 43, 45 whereby the fork-supporting bar 35 is rockable, about a horizontal axis, with respect to the side members 31, 33.

Secured to the bar 35 by bolt-s 46 are spaced parallel forks 47 which are also substantially parallel to the side members 31, 33. In the present embodiment of the invention four forks are shown with the spacing between the two inner forks being greater than the spacing between the inner forks and their adjacent outer forks. The rear or secured ends of the forks 47 are integrally formed with angle shaped horizontal and vertical webs 49 (FIG. 2) for purposes of providing a reinforced connection be- 3 tween the forks 47 and the fork bar 35. Forwardly of the webs 49 the forks 47 are each wider than they are high and include substantially fiat top and bottom surfaces of 51, 53 (FIG. 4). Furthermore, the surfaces 51, 53 of each bar are tapered near the forward end of 54 of each fork to reduce the thickness thereof.

Bolted or otherwise rigidly mounted on the uprights 5, are spaced aligned journal bearings 55, 57 for rotatably supporting a cross shaft 58, the latter also projecting through plates 60, 61 that are welded or otherwise rigidly secured to the uprights 5, 5 inwardly of the bearings 55, 57. Mounted on the cross shaft 58 are spaced pinions 62, 63 that mesh with rack bars 65, 66 that are rigidly mounted on the downwardly presented surfaces of the lower flanges 67, 67 of the side members 31, 33 and which extend lengthwise along the flanges 67, 67. The cross shaft 58 also engages the lower surfaces 53 of the forks 47 to support the forks on the shaft 58.

As best seen in FIGURE 4 the cross shaft 58 projects laterally beyond the bearing 55 for receiving a hand crank 69 that integrally includes a hub 71. The hub 71 is rotatable and axially shiftable on the shaft 58 and has one or more axial slots 72. Adjacent to the hub 70 is a collar 73 that may be secured to the shaft 58 by a key 74. The hub 71 and collar 73 receive the opposite ends of a compression spring 75 that encircles the shaft 58 and that normally biases the hand crank 69 away from the hub 71. When the hand crank 69 is urged toward the collar 72 with one of the slots 76 in alignment with the key 73, the key will slide into the slot 71 so that rotation of the hand crank 69 will impart rotation to the shaft 58. The crank hub 71 is retained on the end of the shaft 58 by a washer 77.

Welded or otherwise rigidly secured to the cross members 8, 8 are plates 79. In the present embodiment of the invention there are six plates with three on each side of the base frame 3. Mounted on the plates 79 and projecting laterally inwardly therefrom are upper and lower studs 81, 82 for rotatably supporting, respectively, upper guide rollers 83 and dual lower guide rollers 84, 85. The upper guide rollers 83 engage the upper flanges of the side members 31, 33 while the lower guide rollers 84, 85 engage the lower flanges 67, 67 on opposite sides of the rack bars 65, 66. The plates 60, 61 each also support upper and lower studs 81, 83 each having their respective guide rollers 83, 84, 85 rotatable thereon. The axes of rotation of the upper guide rollers are all in substantially the same plane, and the same is true of the lower guide rollers.

It will be apparent from the foregoing description that the cross shaft 58 may .be rotated selectively in either direction by the hand crank 69 to drive the pinions 62, 63 which, in turn, drive the rack bars 65, 66 to shift the entire frame 29 forwardly from the retracted position (FIG. 1) to the extended position (FIG. 6) and back again to the retracted position. During the movement between the two positions the side members 31, 33 are guided along linear paths by the upper and lower guide rollers and the forks 47 will shift along and be supported by the cross shaft 58.

Adjacent to their forward ends the webs of the side members 31, 33 have lateral flanges 87, 87 that are adapted to engage stops 88, 88 when the frame 29 is in the retracted position. These stops 88, 88 may be bolted or otherwise mounted onto the plates 60, 61 and project laterally inwardly therefrom. Pivot stops 89, 89 may be mounted on the side members 31, 33 and be engageable with the pivot brackets 43, 45 or to portions of the bar 35 to limit the upward pivotal motion of the fork-supporting bar 35 and forks 47, as will be more fully hereinafter explained.

In use, the forks 47 are normally in their retracted positions as the sheets are being removed one at a time by the mechanism 23 from the top of the stack 21 with the elevator platform 11 being progressively raised to keep the top of the stack in proper feeding position. These sheets are fed from the stack in the general direction in which the tips 54 of the forks 47 point. When the elevator platform has risen to the point where the stack-supporting or top surface 91 of the skid 19 is about level with the forks 47, there will still be a few sheets left in the pile 21, the number remaining being dependent upon the thickness of the individual sheets. For example, where so-called beer sheets of tinplate constitute the stack 21, a fully loaded skid has about eleven hundred to thirteen hundred sheets, and when the skid surface 91 is about level with the forks 47 there will be about one hundred sheets left in the stack with a total stack thickness of about one to one and one-half inches.

The forks 47 are then advanced so that they fit between the lowermost sheet of the remaining sheets of the stack 21 and the top surface 91 of the skid to support the remaining sheets of the stack in position for continued delivery by the mechanism 23. The tapered ends of the forks enable the forks to fit under the stack easily and without any need for special construction of the skid, and the pivotal mounting of the fork bar 35 allows such vertical movement of the ends of the forks as may be necessary to fit under the stack. The elevator platform 11 may then be rapidly lowered to the desired level, the empty skid removed therefrom and another skid 19 (FIG. 6) with a fresh stack of sheets 21 placed on the elevator platform. Such skid 19 may be loaded onto the elevator platform in the direction indicated by the arrow in FIGURE 6 from a conventional roller conveyor (not shown) adjacent to the frame 3 and which contains a plurality of loaded skids. Thereafter the elevator platform may be rapidly raised until the top of the stack 21' abuts the bottoms of the forks 47, whereupon the forks may be retracted from sheet-supporting position leaving the sheets 21 supported thereby as the top group of sheets of the freshly loaded stack.

After the forks 47 have been retracted, they may be swung upwardly so that convenient access may be had to the region below the forks, which is usually where the next skid of sheets is located. This may be accomplished without interruption of the feed of the sheets. The operator of the machine may raise the front ends 54 of the forks, allowing them to pivot about the pivot pins 40, 41. The pivot stops 89, 89 may be located in such positions as to limit the extent to which the forks may be swung. With the forks held in upwardly extended positions, the hand crank 69 may be rotated to shift the entire frame 29 toward its sheet-supporting position until the forks 47 abut a cross bar 93 that extends between the uprights 5, 5, as shown in broken lines in FIG. 6. To prevent accidental movement, of the frame 29 when the forks are upright, the cross bar 93 may have thereon a magnet 94 that attracts one of the forks 47. The frame 29 and forks 47 thereon are, of course, moved to their full line positions, FIG. 1, prior to being used again.

The apparatus may also be equipped with a device to prevent accidental retraction of the forks while they are in position supporting a group of sheets. One such device is shown in FIGS. 7 and 8 and comprises an angle bracket 95 that is bolted or otherwise rigidly secured to the inside of the plate 60 and projects inwardly thereof. A stop bar 96, rotatably mounted on the bracket 95 by a pin 97, is adapted to be manually movable between the full line and broken positions shown in FIG. 8. In the full line position the stop bar 96 rests on a seat 98 that is rigidly joined to the bracket 95.

When the frame 29 is in the sheet-supporting position shown in FIGS. 7 and 8, the stop bar 96 may be shifted to its position on the seat 98, in which position the stop bar 96 will lie behind and close to the end of the top flange of the side member 31. Rearward movement of the frame 29 to retracted position will be arrested by the abutment of the side member 31 against the stop bar 96. However, when it is desired to retract the frame 29, the stop bar 96 is manually swung to the dotted line position, FIG. 8, thus clearing it from the path of movement of the side member 31.

The total time required for the skid changeover cycle consisting of advancing the forks into sheet-supporting position, lowering the elevator platform, removing the empty skid, reloading with another skid, raising the newly loaded skid, and retracting the forks, is relatively short, taking only of the order of one minute.

While the forks are shown as being manually operable, it is apparent that they may be retracted and extended by other means, such as an electric or hydraulic motor.

In compliance with the patent statutes there is herein shown and described a preferred embodiment of the present invention. It should be understood, however, that the invention is not limited to the precise construction herein shown, the same being merely illustrative of the principles of the invention.

What is new and sought to be secured by Letters Patent 1. In a sheet feeding apparatus having an elevator for supporting a stack of sheets and sheet feeding means for removing sheets successively from the top of the stack; means for temporarily supporting, in position for continued successive removal by said sheet feeding means, a plurality of sheets remaining in the stack as the supply of sheets on the stack approaches exhaustion, said temporary supporting means including a frame having a plurality of spaced forks that are in pivotal connection with the frame and are adapted for insertion under said sheets to be supported thereby, driving means for moving the frame to place the forks selectively in sheet-supporting position and for retracting the forks from the sheet-supporting position to enable the elevator to be lowered for reloading with another stack of sheets and then raised to operative position to include in the stack those sheets then supported by the forks, all without ceasing the operation of the sheet feeding means, said frame being rotatable about its pivot axis an amount sufficient to swing the forks to an upright position, and means for maintaining said forks in said upright position.

2. A sheet handling apparatus comprising a base, means fOr supporting a plurality of superimposed sheets, said means including a frame pivotally mounted on the base for movement about a horizontal pivot axis, a plurality of spaced forks secured to said frame, means for shifting the frame to the sheet-supporting position of the forks and to retract the frame therefrom, means forming part of said shifting means for supporting the forks and on which the forks are moved, said frame being rotatable about its pivot axis an amount suflicient to swing the forks to an upright position, means for maintaining said forks in said upright position, and means for mounting and guiding the movement of the frame on the base.

3. A sheet handling apparatus comprising a base, means for supporting a plurality of superimposed sheets, said means including a generally U-shaped horizontally disposed frame having parallel side members and a bight extending between the said members, means forming a pivotal connection between the bight and side members, a plurality of spaced forks secured to said bight and extending between and parallel to the side members, a shaft rotatable on said base and supporting said forks and on which the forks are movable, said shaft having means in operative driving connection with said frame, means for driving said shaft to shift the frame to the sheet-supporting position of the forks and to retract the frame therefrom, and rollers on the base for supporting the frame on the base and for guiding the frame along a rectilinear path.

4. In a sheet feeding apparatus having a base, an elevator for supporting a stack of sheets, and sheet feeding means for removing sheets successively from the top of the stack; means for temporarily supporting, in position for continued successive removal by said removing means, a plurality of sheets remaining in the stack as the supply of sheets on the stack approaches exhaustion, said temporary supporting means including a generally U-shaped horizontally disposed frame having parallel side members and a bight pivotally joined to and extending between the side members, a plurality of spaced forks secured to said bight and extending between and parallel to the side members and having tapered ends for insertion between the elevator and the bottom-most of the plurality of sheets to be supported by the forks, driving means for moving the frame to place the forks selectively in sheet-supporting position and for retracting the forks from the sheetsupporting position to enable the elevator to be lowered for reloading with another stack of sheets and then raised to operative position to include in the stack those sheets then supported by the forks, all without ceasing the operation of the sheet removing means, said driving means including a shaft rotatable on the base and supporting the forks and being in operative driving connection therewith, and rollers on the base above and below the side members and engaging them for supporting them on the base and for guiding the movement of the frame along a rectilinear path as it is moved by the driving means.

5. Apparatus according to claim 4 in which the bight is rotatable about its pivot axis an amount sufficient to swing the forks upwardly to an upright position, and wherein there are means cooperating with the frame for maintaining the forks upright.

6. Apparatus according to claim 4 in which there are cooperating means on the frame and base for arresting movement of the frame when the latter is in sheet-supporting position.

References Cited by the Examiner UNITED STATES PATENTS 1,210,168 12/1916 Heyer 271-87 2,205,767 6/1940 Lamb 271-88 2,690,337 9/1954 Halahan et a1. 2,833,540 5/1958 Koch 271-62 3,180,638 4/ 1965 Meylan.

FOREIGN PATENTS 605,214 7/1948 Great Britain.

M. HENSON WOOD, IR., Primary Examiner.

W. F. MCCARTHY, R. A. SCHACHER,

Assistant Examiners. 

1. IN A SHEET FEEDING APPARATUS HAVING AN ELEVATOR FOR SUPPORTING A STACK OF SHEETS AND SHEET FEEDING MEANS FOR REMOVING SHEETS SUCCESSIVELY FROM THE TOP OF THE STACK; MEANS FOR TEMPORARILY SUPPORTING, IN POSITION FOR CONTINUED SUCCESSIVE REMOVAL BY SAID SHEET FEEDING MEANS, A PLURALITY OF SHEETS REMAINING IN THE STACK AS THE SUPPLY OF SHEETS ON THE STACK APPROACHES EXHAUSTION, SAID TEMPORARY SUPPORTING MEANS INCLUDING A FRAME HAVING A PLURALITY OF SPACED FORKS THAT ARE IN PIVOTAL CONNECTION WITH THE FRAME AND ARE ADAPTED FOR INSERTION UNDER SAID SHEETS TO BE SUPPORTED THEREBY, DRIVING MEANS FOR MOVING THE FRAME TO PLACE THE FORKS SELECTIVELY IN SHEET-SUPPORTING POSITION AND FOR RETRACTING THE FORKS FROM THE SHEET-SUPPORTING POSITION TO ENABLE THE ELEVATOR TO BE LOWERED FOR RELOADING WITH ANOTHER STACK OF SHEETS AND THEN RAISED TO OPERATIVE POSITION TO INCLUDE IN THE STACK THOSE SHEETS THEN SUPPORTED BY THE FORKS, ALL WITHOUT CEASING THE OPERATION OF THE SHEET FEEDING MEANS, SAID FRAME BEING ROTATABLE ABOUT ITS PIVOT AXIS AN AMOUNT SUFFICIENT TO SWING THE FORKS TO AN UPRIGHT POSITION, AND MEANS FOR MAINTAINING SAID FORKS IN SAID UPRIGHT POSITION. 